The objectives of this project broadly stated are to conduct complementary field and laboratory investigations of Schistosoma japonicum infections with emphasis on immune phenomena which might be correlated with clinical disease states. We propose to monitor anti-body and cell mediated immune response including possibly significant associated phenomena in selected population groups living in an area where Schistosoma japonicum is highly endemic. Attempts will be made to correlate these observations with parasitologic and clinical data, with notes of fluctuation or changes over a five year period, and to assess if possible the degree to which the immune phenomena contribute directly to the pathology of the disease. The role of immune renal pathology, autoimmune reactions, antiglobulin antibody and cryoglobulins will be examined. These studies are being carried out as a cooperative program with the Phillipine Department of Health with field studies on Samar and Leyte, The Phillipines. BIBLIOGRAPHIC REFERENCES: Lewert, R.M., Yogore, M.G., Para, J.M., and Ozcel, M.A. 1977. Rejection of mouse derived Schistosoma japonicum and serum lethality of hosts immunized with mouse globulin or mouse erythrocytes. J. Parasit. In press. Jones, C.E., Rachford, F.W., Ozcel, M.A., and Lewert, R.M. 1977. Schistosoma japonicum: semiquantitative assessment of circulating immune complexes, serum C1Q and C3, and the relationship at these parameters to renal pathology and hepatic fibrosis in rabbits. Exp. Parasit. In press.